There has long been an obvious gap in BMW’s product lineup.

While BMW has filled every conceivable niche with its core brand and has gone the other way with MINI, trimming unloved models from its lineup, it's the electrified i brand that has the biggest hole.

It has soldiered on with the ground-breaking i3 and the plug-in hybrid i8, though it has only watched on from the sidelines as Tesla’s 5-Series-sized Model S stole headlines and Audi, Porsche, Mercedes-Benz and Jaguar promised to redraw the battery-electric (BEV) car battle lines.

That’s going to change in 2021, when BMW’s i brand will launch the i-Next, though insiders insist it will be called the i5, and will deliver full Level 4 autonomous driving capability. It will also mimic the 5-Series family by being built with a range of different power outputs and different battery sizes.

Yet even though i is the official in-house electric-car brand, the i-Next or i5 won’t be the next full electric car to come out of the BMW Group.

That will instead be the MINI Cooper E, which will come to market in 2019, though the British-based brand will also launch a plug-in hybrid Countryman next year.

The Cooper E will get a similar 300km NEDC range to the recently upgraded i3

An all-electric X3 will follow that in 2020, the year the EU’s tighter 95g/km fleet average CO2 limits are introduced, with up to 500km of range. Followed by the i-Next.

What’s more, it will be joined a year later by an all-electric version of the 3-Series, with 500km of zero-emission range, to sell alongside petrol, diesel and plug-in hybrid versions of the mid-sized BMW mainstay. The move could prove a crushing blow to Tesla’s hopes of sending its proposed, delayed Model 3 BEV into the mainstream.

Between now and then, though, BMW will electrify every mainstream model it has with plug-in hybrid technology, starting with the 530e iPerformance in March next year and it will also launch a convertible version of the i8 in 2018.

It has seven petrol-electric hybrids available today, but plans to expand that with an upgraded Power E-Drive system, combining two electric motors to give it greater efficiency potential.

It will use one electric motor on the front axle and one on the rear, with one focused on harvesting energy from braking and the other focused on delivering power to the road. The technology will make its debut on the ultra-large 2018 X7 SUV, but will fit both front- and rear-drive layouts.

But the i-Next is planned to be the step-change at BMW, introducing a new world of hands-free driving on highways and in city environments, along with ringing in a new era of digitization, connectivity and a bigger interior package.

“Our Strategy Number One Next is centred on consequent lightweight construction, alternative drivetrain technology, connectivity, autonomous driving functions and the interior of the future. The iNext will set the standard from 2021,” says Krüger.

While there was a flurry of speculation earlier this year about an early appearance for an i5 after BMW’s patent applications for its Z32 research car, the i5 won’t be a high-riding SUV after all.

Instead, it will be a sleek four-door sedan or liftback, with its exterior dimension roughly similar to the all-new, seventh-generation 5-Series.

The car will be built at BMW's Leipzig factory in Germany, which became known for its carbon-fibre competency during the i3's development.

“With the BMW i NEXT, our goal is to create a sustainable, fully-connected self- driving premium vehicle,” BMW’s director of development, Klaus Fröhlich, insisted.

“It will be the most advanced and modern form of individual mobility.”

BMW has learned its lessons from the i3, with insiders admitting it made a mistake prioritizing weight reduction over scalability. That left BMW without the ability to easily and quickly deliver a larger BEV based on the rear-engined i3’s mechanical package, and it’s a mistake it doesn’t plan to repeat.

“The architecture of BMW Group vehicles is designed in a way that allow further rollouts with short lead times, as demand for electrified vehicles continues to grow,” Fröhlich insisted.

“The third generation of BMW electric drivetrains is already in series production and we have begun developing the generation after that for 2020 and beyond.

“By then, progress in battery cell technology will allow the BEV to become an increasingly normal drive variant for many BMWs, MINIs and Roll-Royce.”

The Tesla Model S is a 2100kg car and the i-Next won’t be anything like that heavy, utilizing carbon-fibre (BMW claims it uses 10 percent of the world’s carbon-fibre today), aluminium and magnesium to hit a target weight of closer to 1700kg.

The larger floor area will give the i-Next a flatter battery pack, which makes the car’s architecture more modular and which it will share with its platform twin, the BEV SUV i6, which will arrive in 2022.

Far cheaper to build than the i3’s intensely exotic body, the i-Next architecture is also sophisticated enough to deliver a successor to the i8 with both plug-in hybrid and BEV powertrains.

It will drive the wheels via BMW’s new generation of synchronous electric motors which will offer a wide range of outputs at different price points.

The motor is planned to spin faster than the current range of BMW electric motors and will offer even V8-style power outputs in a BEV the size of a 5-Series, plus a larger 7-Series-sized limousine in 2024.

The base i-Next is planned to have around 550km of range from a 110kWh battery (20kWh more than the strongest Model S), though the top level with the highest power output will add around 100km to that.

Each of the cells is just 110mm high, which will make them the most compact predicted units on the market and considerably smaller than the ones in Daimler’s upcoming EQ BEV family or Jaguar’s I-Pace.